This invention relates generally to detecting a location of a vehicle, and more particularly to detecting the presence of a vehicle in a railroad crossing.
Train-vehicle accidents may occur at railroad crossings when drivers ignore or do not observe warning systems such as gates, flashing lights, or warning signs. The railroad industry and state transportation authorities regularly engage in construction projects to increase safety at these crossings, particularly drawing on accident statistics for prioritizing potential projects.
Previous attempts for accomplishing the increase in safety have been hindered by the cost and lack of precision of detection technologies such as infrared, light beams and photocells, and microwave security intrusion sensors. The accuracy of these technologies can vary widely over time, temperature, and weather conditions. Ice, snow, rain, and dust can render them inoperative.
Buried impedance loop systems are used at some railroad crossings. Impedance loops are buried under the crossing and are connected to a monitoring device that can control the raising and lowering of gates at a rail crossing. The presence of a vehicle within the crossing causes an impedance within the buried loop circuit to change, the impedance change being detected by the monitoring device, which then causes the gates to open, allowing the vehicle to exit. Drawbacks to the buried impedance loop systems include that while the system can detect vehicles, the system does not detect pedestrian traffic. In addition, buried impedance loop systems are costly to install and maintain.
In one aspect, a method for collecting railroad crossing data is provided. In an example embodiment, the method comprises detecting a presence of at least one of a pedestrian and a vehicle within a boundary of the railroad crossing, storing a count of the presence of pedestrians and vehicles detected within the boundary, and transmitting the count to an external device.
In another aspect, a railroad crossing system is provided. In an example embodiment, the system comprises at least one micropower impulse radar (MIR) unit configured to detect a presence of at least one of a pedestrian and a vehicle within a boundary of a railroad crossing, a remote terminal unit (RTU) coupled to the MIR unit and configured to store a count of the presence of pedestrians and vehicles detected within the boundary by the MIR unit and further configured to communicate the counts, and a computer system configured to receive the counts communicated by the RTU.
In still another aspect, a method for monitoring a plurality of railroad crossings is provided. In an example embodiment, the method comprises collecting railroad crossing data for each railroad crossing, storing the railroad crossing data, selecting a sorting criteria, and sorting the railroad crossing data using the selected sorting criteria.
In yet another aspect, a system is provided which comprises at least one computer and a plurality of micropower impulse radar (MIR) units. The MIR units are deployed at a plurality of railroad crossings, at least one MIR unit per railroad crossing. The MIR units deployed at each crossing are configured for detecting a presence of at least one of pedestrians and vehicles within a boundary of the railroad crossing where deployed. The system further includes a plurality of remote terminal units (RTUs), each of the MIR units connected to one of the RTUs. The RTUs are configured to store a count of the presence of pedestrians and vehicles detected within the boundary by said MIR units and further configured to communicate at least the counts to the computer. The computer is further configured to determine elevated risk railroad crossings based upon the counts received from the plurality of RTUs.
In another aspect, a railroad crossing system is provided which comprises at least one crossing gate arm, a number of impedance loops buried under the railroad crossing, and a gate control mechanism connected to the impedance loops and configured to raise the crossing gate arms upon detection of a vehicle within a boundary by the impedance loops. To augment the impedance loops and control mechanism, the system further comprises at least one micropower impulse radar (MIR) unit configured to detect vehicles within the boundary and at least one remote terminal unit (RTU) connected to the MIR units. The RTU is configured to communicate with the gate control mechanism.
In still another aspect, a method for detecting trapped vehicles within a railroad crossing is provided. The railroad crossing includes impedance loops buried under the crossing, within a crossing boundary, which are connected to a gate arm control mechanism, which is further connected to one or more gate arms. The railroad crossing further includes at least one micropower impulse radar (MIR) unit configured to detect vehicles within the boundary and at least one remote terminal unit (RTU) connected to the MIR units and further configured to communicate with the gate arm control mechanism. The method comprises lowering the gate arms upon approach of a train, thereby defining a boundary, checking for vehicles trapped within the boundary using the impedance loops and gate control mechanism and separately with the MIR units and the RTU, raising the gate arms if a vehicle is detected, repeatedly checking for vehicles until no vehicle is detected, and lowering the gate arms.